The invention relates to an electrical connection assembly and more specifically to a clamp-on multiple lug buss bar assembly that would be utilized with a transformer located in an underground vault.
Presently when making electrical connections to a transformer in an underground vault, there can be a major height or space problem in the interior. The terminals of the transformer extend upwardly from its top surface in the form of threaded stud members. Transformer lugs are usually attached. Spade buss moles or other multiple attachment devices may then be bolted into a lengthy assembly, which may cause the service cables to be bent severely and interfere with their installation. This assembly is entirely supported by the threaded stud of the transformer. Thus the assembly and the associated cables attached to it, can by moment arm and mass, lever the stud to the point of cracking the epoxy seal surrounding the threaded stud. This would cause the premature failure of the transformer.
The assembly is made by connecting pieces of different metals. In order to protect the assembly against moisture, electrolysis and electrically insulate, sealant and protective tapes are hand placed around it. This taping is a labor intensive operation and it involves many repetitive motion acts of the nature which contributes to xe2x80x9cCarpal Tunnel Syndromexe2x80x9d.
It is an object of the invention to provide a novel clamp-on multiple lug buss bar assembly having a much reduced height for use on a transformer in an underground transformer vault.
It is also an object of the invention to provide a novel clamp-on multiple lug buss bar assembly with a wide base that distributes the stress on the threaded stud electrical terminal of the underground transformer.
It is another object of the invention to provide a novel clamp-on multiple lug buss bar assembly that completely encapsulates the threaded stud electrical terminal on the top of the transformer into a premolded form.
It is an additional object of the invention to provide a novel clamp-on multiple lug buss bar assembly that is easily and quickly installed on the threaded stud electrical terminal of a transformer.
It is a further object of the invention to provide a novel clamp-on multiple lug buss bar assembly that is economical to manufacture and market.
It is also an object of the invention to provide a simple and economical system of electrically connecting any two studs of a four stud transformer.
The clamp-on multiple lug buss bar assembly has been design primarily for use in an underground transformer vault. The basic components are a two-piece nut unit, a pair of conductor plates having different configurations, a spacer block and a connecting buss member. With these different components, various assembled embodiments can be made depending on the specific application.
Once the required components have been decided upon, they are assembled together in a loose fashion so that the two-piece nut unit can be mounted on the threaded stud electrical terminal extending from the top surface of a transformer. Once the internal threads of the two-piece nut unit have been matched with the threads of the stud, the nuts are tightened on the bolts holding the components together and the entire structure becomes a rigid structure. Next a mold is placed over the top of the conductor plates and the top of the mold would be slightly above the top edge of the body portion of the conductor plates. The spade connector fingers would extend upwardly through apertures in the top wall of the mold. Riser tubes would be inserted into these apertures and surround the individual spade connector fingers. Alternatively, the risers could be integrally formed with the top wall of the mold. Next an epoxy resin would be poured into the cavity formed in the mold through the risers and it would adhere to the top surface of the transformer and provide a watertight seal surrounding the threaded stud electrical terminals. Each of the spade connector fingers would benefit from the distribution of the stress to threaded stud electrical terminals by the solid mass of epoxy that extends laterally from the axis of the stud members. The mold could be left in place but it is preferable that it be quickly disassembled so that it can be reused. The reduced height of the clamp-on multiple lug buss bar assembly allows the spades of the secondary electrical distribution cables to be connected to the top of the respective spade connector fingers and have a gradual curved configuration as they travel upwardly and transversely to their distribution destination. Molds of a larger configuration could be used when two studs are joined, thus encapsulating the buss internally. This could be used to parallel the two 120V coils of a four stud transformer (two large moldings) or connect in series for a 120/240V three wire (one small molding on each side and one large molding for the neutral connection).